JP2003314592A - Clutch control device for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an excellent traveling feeling without the necessity of rematching by a vehicle when changing the relation between a transmission torque of an electromagnetic powder clutch and an exciting current. <P>SOLUTION: The synchromesh automatic transmission comprises an electromagnetic powder clutch for executing the transmission and cut-off of power and the creep control at the start and end of the gear-shift. The control means includes the clutch control part for travelling a vehicle at low speed by supplying the exciting current to the electromagnetic powder clutch to bring the electromagnetic powder clutch to a fastened or semi-fastened state when the shift position is at a traveling range or reverse range. When detection by the brake switch and the accelerator position is not found, the clutch control part converts the clutch transmission torque, calculated according to the deviation signal obtained by a close loop control based upon deviation between target vehicle speed and actual vehicle speed, into the exciting current on the basis of the prescribed characteristics of relationship with the exciting current. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch control device for an automatic transmission, and more particularly to a stable traveling technique during creep traveling.

[0002]

2. Description of the Related Art Conventionally, as a vehicle engine clutch control method, for example, there is a method referred to in Japanese Patent Application Laid-Open No. 6-159398. As is well known, the automatic transmission has a creep function, and the signal from the range switch detects that the shift position is the forward or reverse position, and the signal from the accelerator position sensor does not step on the accelerator. When it is recognized that the vehicle is in a running state, a creep current is applied so as to facilitate driving on a congested road or in a garage.

In the device described in the above publication, when the vehicle is traveling at a low speed with the electromagnetic powder clutch engaged or semi-engaged, and the accelerator is not stepped on,
The exciting current value for energizing the electromagnetic powder clutch, that is, the creep current value is calculated from the program map corresponding to the vehicle speed, or by calculating the vehicle speed as a variable, the vehicle speed changes depending on the load of the vehicle, road conditions, etc. To prevent that.

[0004]

Since the conventional clutch control device for an automatic transmission calculates the creep current value as described above, the relationship between the transfer torque and the exciting current of the electromagnetic powder clutch is changed due to design changes and the like. There has been a problem in that, when changed, the vehicle needs to be re-matched.

Further, when the creep current value corresponding to the vehicle speed is calculated from the program map, there is a problem that an appropriate driving force cannot be obtained for a slight slope such as an uphill slope.

The present invention has been made in order to solve the above-mentioned problems, and there is no need for re-matching by the vehicle when the relationship between the transmission torque of the electromagnetic powder clutch and the exciting current is changed, and there is no need for re-matching. It is an object of the present invention to obtain a clutch control device for an automatic transmission in which the driving feeling does not change depending on the road surface condition.

[0007]

A clutch control device for an automatic transmission according to the present invention is a clutch control device for an automatic transmission that automatically switches a plurality of gear stages, and is an engine for detecting a rotational speed of an engine. A rotation sensor, a brake switch that detects the state where the brake pedal is depressed, a range switch that detects the shift position, which is one of the running range, neutral range, and reverse range, and the accelerator pedal depression amount. , A vehicle speed sensor that detects the output rotation speed of the synchromesh transmission as a vehicle speed, and detection signals of the engine rotation sensor, the brake switch, the range switch, the accelerator position sensor, and the vehicle speed sensor. Shift of the synchronous mesh type transmission based on And a control unit for switching the state, wherein the synchromesh transmission includes an electromagnetic powder clutch for performing power transmission, interruption, and creep control at the start and end of the shift, and the control unit has the shift position as the shift position. By supplying an exciting current to the electromagnetic powder clutch in the traveling range or the reverse range, the electromagnetic powder clutch is engaged or semi-engaged to include a clutch control unit for driving the vehicle at a low speed. When there is no detection by the brake switch and the accelerator position, the clutch transmission torque calculated according to the deviation signal obtained by the closed loop control based on the deviation between the target vehicle speed and the actual vehicle speed is set to a predetermined relation characteristic with the exciting current. Based on this, it is converted into an exciting current.

An upper limit value is set for the clutch transmission torque, and the clutch control unit converts the transmission torque into a predetermined exciting current when the transmission torque is equal to or higher than the upper limit value.

Further, the clutch control section makes a predetermined correction on the clutch transmission torque when the engine speed is out of a predetermined range.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings. 1 is a block diagram schematically showing a first embodiment of the present invention.

In FIG. 1, a crankshaft 2 of an engine 1
A synchronous mesh type stepped transmission 3 (hereinafter, simply referred to as “stepped transmission 3”) that constitutes a synchronous mesh type automatic transmission is connected to 1 via an electromagnetic powder clutch 2.

The control unit 4 includes a microcomputer having various calculation functions, and based on various sensor information indicating the operating state of the engine 1, the engine 1,
The electromagnetic powder clutch 2 and the stepped transmission 3 are controlled.

The shift / select actuator 5 drives the stepped transmission 3 under the control of the control unit 4. The shift / select position sensor 6 detects the actual shift / select positions VY and VX of the stepped transmission 3 and inputs them to the control unit 4.

A fourth speed gear 23, which functions as a primary gear, is directly connected to the input shaft 22 of the stepped transmission 3. After the fourth gear 23, the third gear 24,
A second speed gear 25, a first speed gear 26, a fifth speed gear 27, and a reverse gear 28 are sequentially arranged.

Three sleeve gears 29 are arranged between the gears 23 to 28. Each sleeve gear 29 is
It is directly connected to the output shaft 30 of the stepped transmission 3 and is movable in the axial direction.

The gears 23 to 28 form a set with a gear directly connected to a counter shaft 31 provided in parallel with the output shaft 30 and always mesh with a gear on the counter shaft 31.

With the above structure, the output shaft 3
0 is directly connected to the input shaft 22 by being directly connected to any of the gears 23 to 28 via the sleeve gear 29.

In this case, the stepped transmission 3 is a counter shaft type five-stage gear transmission, and includes five forward gear sets having different gear ratios, one backward gear set, and a gear meshing state switching device. And three sleeve gears.

Fourth speed gear 23 on the input shaft 22
Is provided with an input rotation speed sensor 7 for detecting the input rotation speed Ni of the stepped transmission 3. The output shaft 30 is provided with an output rotation speed sensor 8 for detecting the output rotation speed of the stepped transmission 3 as a vehicle speed Vr.

A throttle valve 1 driven by a throttle actuator 11 is installed in an intake pipe 9 of the engine 1.
0 is provided. Throttle position sensor 12
Detects the opening θ of the throttle valve 10.

The accelerator position sensor 13 uses a signal proportional to the amount of depression of an accelerator pedal (not shown) by the driver as the accelerator opening α to the control unit 4.
To enter.

The control unit 4 processes the output signal of the accelerator position sensor 13 to calculate a target throttle opening θo corresponding to the accelerator opening α, and feedback (F / B) controls the throttle opening θ. , Θ
The throttle valve 10 is driven via the throttle actuator 11 so that = θo.

The shift lever 14 is a shift position operated by a driver (for example, parking range P, reverse range R, neutral range N, travel range D).
To the control unit 4. The engine rotation speed sensor 15 detects the rotation speed Ne of the engine 1 and inputs it to the control unit 4.

The reverse gear 28 in the stepped transmission 3 is provided with a reverse gear switch 16 to detect the operating state of the reverse gear. The brake switch 17 inputs to the control unit 4 a signal indicating a brake operation state while the driver is stepping on a brake pedal (not shown).

The control unit 4 determines the shift based on various sensor signals, controls the shift / select actuator 5 in accordance with the shift determination, and determines the shift pattern (shift diagram) based on the accelerator opening α and the vehicle speed Vr. A gear stage is set to a required gear stage, and a plurality of gear stages of the stepped transmission 3 are automatically switched.

Next, the basic operation according to the first embodiment of the present invention shown in FIG. 1 will be described. The electromagnetic clutch 2 is driven by a clutch exciting current proportional to the clutch transmission torque under the control of the control unit 4,
Power transmission (or interruption) from the crankshaft 21 of the engine 1 to the input shaft 22 of the stepped transmission 3 is controlled.

In the stepped transmission 3, the input rotation is as follows. First, the frontmost primary gear (input shaft 2
It is transmitted to the counter shaft 31 from 2). The output shaft 30 is extended to the front of the third speed gear set, and the transmission path and the gear ratio (gear ratio of the primary gear x gear ratio of each speed gear) change depending on which of the gears on the output shaft 30 is connected. To do.

In the fourth speed, the input shaft 22
And the output shaft 30 are directly connected. In the stepped transmission 3, the sleeve gear 29 is shift-controlled by the shift / select actuator 5 for gear switching, and the gear shift operation is performed.

That is, the stepped transmission 3 shifts the sleeve gear 29 to mechanically disengage the gears of the current gear and the gears of the next gear. It is switched to connection operation.

The control unit 4 includes an operation position of the shift lever 14, an accelerator opening α, a stepped state of a brake pedal (not shown), a rotation speed Ne and a vehicle speed V.
The optimum shift speed is set from the shift pattern based on r, and the shift / select position sensor 6 detects the shift / select position while the shift / select actuator 5
To control.

The synchronous state of the sleeve gear 29 is detected from the input / output rotational speed relationship detected by the sensors 7 and 8. When shifting, the throttle actuator 1
The throttle opening θ is narrowed to a predetermined opening position by 1 and the exciting current of the electromagnetic clutch 2 is set to 0 to put the multi-stage transmission 3 in the power-off state to switch the gear.

Next, referring to the creep feedback control block diagram of FIG. 2, the first embodiment of the present invention will be described.
The specific operation of the above will be described. FIG. 2 is a block diagram of a portion for calculating a clutch exciting current value during creep closed loop control.

In FIG. 2, 100 is a subtractor for calculating the deviation between the target vehicle speed and the actual vehicle speed, and 110 is a proportional gain for multiplying the deviation signal obtained by the closed loop control based on the deviation by the subtractor 100 by a proportional coefficient K _P. And the proportional term (P term) is calculated. 120 is an integral term (I
This is a switch (SW) for switching whether or not to calculate the term).

This switch 120 is used to stop the calculation of the integral term (I term) when the upper limit value is reached in the upper limit process of the clutch transmission torque value described later.
When the switch 120 is selected to have the integral term (I term) calculated, the integral term (I term) is calculated with 1 / S130 and the integral gain K _I 140. As described above, the proportional term (P term) and integral term (I term) calculated respectively are added to the adder 150.
And the clutch transmission torque value is calculated.

Next, 160 is the engine speed sensor 1
5 is a torque correction unit that performs a predetermined correction on the clutch transmission torque value when the rotational speed Ne of the engine 1 detected by 5 exceeds a predetermined upper limit value and a lower limit value.
A predetermined correction amount is added by 65.

By the processing of the torque correction section 160, the effect of preventing the engine stall when the engine speed is low and the engine blowing up when the engine speed is high is obtained.

Next, the upper limit processing unit 170 performs the upper limit processing of the clutch transmission torque value. That is, the upper limit processing unit 17
When the clutch transmission torque value input to 0 is larger than a preset value, a predetermined clutch transmission torque value is output so that a clutch transmission torque value exceeding a certain value is processed. ing.

By providing the upper limit processing in this way,
A vehicle equipped with the clutch control device of the present automatic transmission can strongly climb up a slope having a certain degree of slope and prevent engine stall on a slope having a higher slope.

Further, in the table conversion section 180, the clutch excitation torque value subjected to the upper limit processing is applied to the map data showing the predetermined relation characteristic between the clutch transmission torque and the clutch excitation current as shown in FIG. To calculate. The map data shown in FIG. 3 is an example, and varies depending on the characteristics of the electromagnetic powder clutch 2, for example, the number of electromagnetic windings forming the electromagnetic powder clutch 2 and the amount of powder inside.

FIG. 4 is a timing chart showing changes in the clutch actual current and the actual vehicle speed after the vehicle is stopped. In FIG. 4, when the brake SW is turned off, the clutch actual current (clutch excitation current) is necessary to set the actual vehicle speed calculated based on the closed loop control shown in FIG. 2 with a certain control time difference as the target vehicle speed. The current value corresponding to the clutch transmission torque is increased.

With the supply of the clutch actual current, the actual vehicle speed gradually increases to the target vehicle speed, and even after reaching the target current,
By the closed loop control, the actual vehicle speed converges to the target current and a stable driving feeling can be provided.

As described above, according to the clutch control device for the automatic transmission of the present embodiment, the clutch transmission torque calculated according to the deviation signal obtained by the closed loop control based on the deviation between the target vehicle speed and the actual vehicle speed. By converting the value into an exciting current based on a predetermined relationship characteristic (map data) with the exciting current, the vehicle is rematched when the relationship between the transmission torque of the electromagnetic powder clutch 2 and the exciting current is changed. It is possible to provide a stable driving feeling without the need.

[0043]

According to the clutch control device for an automatic transmission according to the present invention, the clutch transmission torque calculated according to the deviation signal obtained by the closed loop control based on the deviation between the target vehicle speed and the actual vehicle speed is set as the exciting current. By converting the exciting current into the exciting current based on the predetermined relational expression, it is not necessary to rematch the vehicle when the relationship between the clutch transmission torque of the electromagnetic powder clutch and the clutch exciting current is changed.

Further, an upper limit value is set for the clutch transmission torque, and the clutch control unit converts the transmission torque into a predetermined exciting current when the transmission torque is equal to or higher than the upper limit value, thereby forcibly climbing up to a certain slope. Engine stall can be prevented on slopes with a higher slope.

The clutch control unit corrects the clutch transmission torque when the engine speed is out of the predetermined range, so that the clutch transmission torque is reduced when the engine speed sharply decreases. Stalls can be prevented.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram according to the first embodiment of the present invention.

FIG. 3 is a data map showing a relationship characteristic between the clutch transmission torque and the clutch exciting current according to the first embodiment of the present invention.

FIG. 4 is a timing chart diagram of the first embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 engine, 2 electromagnetic powder clutch, 3 stepped transmission (synchronized mesh type transmission), 4 control unit (control means), 8 output rotation speed sensor (vehicle speed sensor), 13 accelerator position sensor, 14 shift lever (range switch) ), 15 engine rotation sensor, 17 brake switch.

Claims (3)

[Claims] 1. A clutch control device for an automatic transmission that automatically switches between a plurality of gear stages, the engine rotation sensor detecting an engine rotation speed, and a brake switch detecting a state in which a brake pedal is depressed. Range switch that detects the shift position, whether it is the running range, the neutral range, or the reverse range, the accelerator position sensor that detects the depression amount of the accelerator pedal as the accelerator opening, and the output rotation speed of the synchromesh transmission. A vehicle speed sensor that detects the vehicle speed as a vehicle speed, and a control unit that switches the shift state of the synchromesh transmission based on the detection signals of the engine rotation sensor, the brake switch, the range switch, the accelerator position sensor, and the vehicle speed sensor. And the synchromesh transmission is The electromagnetic powder clutch includes an electromagnetic powder clutch that performs power transmission, interruption, and creep control at the start of shifting and at the end of shifting, and the control means applies an exciting current to the electromagnetic powder clutch when the shift position is the traveling range or the reverse range. By including a clutch control unit for driving the vehicle at a low speed by supplying the electromagnetic powder clutch in the engaged or semi-engaged state, the clutch control unit, when there is no detection by the brake switch and the accelerator position, the target vehicle speed and A clutch for an automatic transmission, characterized in that a clutch transmission torque calculated according to a deviation signal obtained by a closed loop control based on a deviation of an actual vehicle speed is converted into an exciting current based on a predetermined characteristic of a relationship with the exciting current. Control device. 2. The clutch transmission torque is provided with an upper limit value, and the clutch control unit converts into a predetermined exciting current when the transmission torque is equal to or higher than the upper limit value. Clutch control device for automatic transmission. 3. The clutch control section applies a predetermined correction to the clutch transmission torque when the engine speed is out of a predetermined range.
Alternatively, the clutch control device for the automatic transmission according to item 2.